Washing machine having balancer and control method thereof

A washing machine having a balancer includes a rotating basket in which laundry is accommodated, the rotating basket being configured to be rotated upon receiving rotation power from a drive source, at least one balancer housing mounted to the rotating basket, the balancer housing internally having an annular channel, and at least one balancing module movably disposed in the channel to alleviate load unbalance caused during rotation of the rotating basket. The balancing module includes a main plate, at least one mass body provided at the main plate, a drive unit mounted to the main plate to assist the balancing module in moving to a position where the balancing module alleviates load unbalance of the rotating basket, and a brush configured to transmit electric power supplied from an external power source to the drive unit.